fix(package): update downshift to version 5.4.2

Closes #793

Author: greenkeeper[bot]

packages/admin-ui/package.json

@@ -25,7 +25,7 @@
     "@types/react": "^16.7.2",
     "@types/react-dom": "^16.0.9",
     "deepmerge": "^3.0.0",
-    "downshift": "^3.1.4",
+    "downshift": "^5.4.2",
     "emotion": "^10.0.0",
     "history": "^4.9.0",
     "interweave": "^9.2.1",